Neuroendocrine neoplasms form a heterogeneous group of neoplasms that represent 1% of all digestive malignancies. Mixed Neuroendocrine-Non- Neuroendocrine Neoplasms (MiNEN), are defined by the combination of at least two morphologically different neoplastic components, including a neuroendocrine component usually poorly differentiated neuroendocrine carcinoma. The non-endocrine component is mostly adenocarcinoma. Squamous cell carcinoma is rarely associated. Evidence from the literature on MiNENs is almost derived from case reports and small retrospective series.
